Ethylene–potassium interactions safeguard ionic balance, chlorophyll biosynthesis, and source–sink metabolism to sustain wheat growth and yield responses under salt stress

Significant reduction in crop yields has been caused due to salt-impacted agricultural soils. In order to meet hunger requirements, significant solutions are required for speeding up agricultural production even in salt-impacted soils. As salt stress reduces the uptake of potassium (K⁺), replenishing the K⁺ nutrition may serve as a tolerance mechanism. The present study investigated the different K⁺ levels (low, optimum, and excess) along with a stress hormone, ethylene in modulating plant responses under salt stress. The results demonstrated that the interplay of ethylene and K⁺ significantly altered salt induced inhibition through improved K⁺retention, chlorophyll biosynthesis, and source-sink metabolism to protect growth and yield traits. Additionally, ethylene and K⁺ improved key pathways such as defense machinery, nitric oxide (NO) biosynthesis along with secondary metabolites (lignin, cellulose, flavonoid and phenol) to overcome salt-induced adversities. The impacts posed by the interplay between ethylene and different K⁺ levels depicted a variable mitigation of salt induced adversities. Conclusively, ethylene and optimum K⁺ treatment best excruciated the salt-inhibited responses. Supplementation of norbonadiene (NBD, ethylene action inhibitor) further confirmed the role of interplay between ethylene and differential K⁺ concentrations in mediating the salt stress responses. The present study pose as a significant strategy towards cultivar development programs to counter salt-inhibited constraints and paves way to ensure crop security.